physorg.com — A Purdue University engineer has developed a method that uses an aluminum alloy to extract hydrogen from water for running fuel cells or internal combustion engines, and the technique could be used to replace gasoline.
May 16, 2007 View in Crawl 4
bestenemyMay 17, 2007
Aluminum is recycled not through re-composition of it from the waste chemical product but from one shape into another - melting pop cans into bikes, cars etc. Aluminum is abundant, but if we start using it at the same rate as oil the price will go up. It's vital for construction due to its qualities - conductivity, magnetic passiveness, lite weight, durability. Nano technology is not sufficient at the current state for replacing aluminum, and if we can't do that, I'm hesitant to wasting aluminum on fuel. If aluminum is so cheap and abundant, how come car bodies aren't all made of aluminum yet? Huh? Shouldn't the benefits of weight reduction, rust resistance and consequent fuel saving outweigh the cost difference between iron and aluminum? I'd rather save fuel though costs associated with transportation and maintenance, than turn renewable resource (that does not get chemically altered) into a non-renewable offset for the problem.
bestenemyMay 17, 2007
You'll love this part! Taken off wikipedia:"Some flue dusts from burning coal have been shown to contain as much as 1.5 percent gallium." Despite it being used only as a catalyst in proposed hydrogen production, it does not exist in raw form. Each purification method is highly toxic and wasteful in terms of energy. Gallium is currently priced at $400/kg. If demand rises it will make it even more expensive. Purification relies on compounds that are even more rare and expensive. Gallium can be extracted using reverse salt fusion electrolysis. Guess what? We're using electricity! Aren't we converting hydrogen into it at the end having wasted 90% of juice on countless transitions? This project is a run-around and a waste of energy. It offers no benefits. We're not using electrolysis to get hydrogen, but we still need it to convert byproducts back into reagents. That's a slide of hand trick. This is no solution.
billybobfettMay 17, 2007
vikingcoder: thanks for the link; I hadn't seen that information before.
bestenemyMay 18, 2007
We're not running out of sources of energy, we're running out of cheap renewable sources of energy. There are plenty of expensive non-renewable ones (such as the one proposed here) and there is expensive renewable ones such as wind, solar, there are geographically dependant ones such as hydro and nuclear. First one directly dependant, second one "psychologically" dependant for the reason people want clean energy but are more afraid of Cernobyl than they were of Communism during the cold war. There's been a huge demand for solar energy, yet it has gotten only marginally cheaper.Since we're at the stage where we're allowed to throw links at eachother I'll give you a few on hydrogen economy.<a class="user" href="http://www.physorg.com/news85074285.html">http://www.physorg.com/news85074285.html</a> - compares chemical energy battery technology with hydrogen tech. Although the current article is too recent to have been a part of this publication, you can substitute the 50% alumina recycling efficiency into the equation in replacement of existing 75% electrolysis of water part.<a class="user" href="http://www.thewatt.com/article-901-nested-1-0.html">http://www.thewatt.com/article-901-nested-1-0.html</a> - efficiency comparison of battery technology to fuel cell alternative.<a class="user" href="http://www.thewatt.com/article-1238-nested-1-0.html">http://www.thewatt.com/article-1238-nested-1-0.html</a> - has an audio link, if you're not into reading lengthy paragraphs. Gives a series of comparisons My favourite quite there is: "If the entire traffic at Frankfurt Airport was all done with hydrogen, one would need the water consumption of the City of Frankfurt plus about 25 nuclear power plants. Using hydrogen for all public air and road transport in Germany, it would take the power output of about 400 nuclear power plants plus enormous amounts of water. You need nine kilograms of water to make one kilogram of hydrogen. The Rhine river and all other rivers would be dry in the summer because the water is used to make hydrogen. So, we are really approaching limits and we have to talk about these limits before we talk about a hydrogen economy." I see our problem is in our consumption demands. If we keep throwing energy away, as if it was free, it won't matter where we extract it from. There'll never be enough of it. I'm for physical efficiency and that implies fewer conversions. Aluminum method has too many steps. Through each one energy is lost. We're using some to mine aluminum, some mine gallium, transportation of ore, reaction, transportation of either hydrogen or raw materials the atomic weight of which is higher than that of hydrogen. Compression of hydrogen. Inefficient conversion into electricity through fuel cells. Transportation of waste product back to the power plants. The most important part is the weight of alumina - Al2O3 has the atomic weight of 101.96 compared to 1.01 for hydrogen. Which means, for every kg of hydrogen fuel you get from the plant you have to move 100kg of recyclible waste. How's that more efficient than just using the damn nuclear plant to extract hydrogen through electrolysis out of the same water that's supplied for chamber cooling and steam turbines? The method proposed in this article leaves out tons of details each one of which costs money and energy. The sum of all makes already inefficient hydrogen economy even more inefficient. It does not solve anything. It only creates a bigger problem.
bestenemyMay 18, 2007
Benefit of Li-Ion is that the material doesn't get used up. Sure, Al might store more energy, but it makes little difference, if we're only able to extract less than 45% of that energy out of dual conversion into hydrogen and electricity. Why not just link Li-Ion straight to the engine? Aluminum, has higher atomic weight of almost 27. Hydrogen has 1. There is absolutely no way Al + Ga + H20 is going to be lighter than H2 that gets produced during the reaction. Water required to produce hydrogen sufficient for subsituting 1L of oil, as far as I remember is close to 9L. So, we're carrying more than 9 times the weight on board before we even come close to what we used to have with gasoline engine. Also there is aluminum and oxidation catalyst galium that is even heavier that the aluminum. Have you watched the experiment? Thy had a beaker fool of galium with a few visible pellets of Al. If that is the actual required volumetric proportion, then I'm not impressed at all. Gallium, regardless of being a catayst is quite expensive. Expect that initial payment on your car being no less than that of a lithium battery pack at $400/kg... that is if they choose to stick with hydrogen conversion unit on board. I'm now hearing that they would do it at a stationary location. Perhaps gas station that look like grain silos. Anyways, the article presents a complex multi-step solution. It fails to elaborate on all the potential implications. It only picks a few. Burried down the fact it produces large quantities of weight by volume, compared to the fuel extracted. Aluminum might be abundant, but it's not the only cyclable element in the equation. Put all the elements together, combine mining, refining, transportation, loss of energy due to multiple conversions, transportation and decomposition of waste product and you'll realize that simple electrolysis of water and electrochemical alternatives aren't as inefficient as they once appeared. Article fails to elaborate on atomic wights of the components, total loss of energy and financial implications of required transportation to make the whole economy possible. It also fails to mention construction cost breakdowns. Electrolysis plants are simple. They're just too inefficient at this point compared to oil. But if we're talking hydrogen plants next to eachother - electrolysis one would win over Al,Ga plant effortlessly. Simplicity of setup and application is a huge factor.
Closed AccountMay 21, 2007
Well as expensive as such a process would be, the cost is a one-time investment. You aren't buying new pellets, slugs, every time you employ them.the only ongoing cost would be the cost to recharged them.Every process that generates energy for practical implementations, for use in machinery, is going to produce waste.Even it we use pure hydrogen the water would not be clean once leaving the machine.It would be waste water. And millions of gallons of waste water. The roads would be like rain soaked roads all the time and the dirty water would get everywhere.The highly explosive relationship between oxygen and hydrogen would require such complicated safety mechanisms and followup procedures to avoid abandoned potential bombs that those costs would be pretty prohibitive.This idea seems to me a rather efficacious one.IMHO anyway
water4fuelAug 24, 2008
"Can they come up with ways to use s**t" @lazyliberal Well, as a matter of fact; "The Orange County Sanitation District is about to begin converting human waste into hydrogen fuel"<a class="user" href="http://hydrogen-fuel-cell-car.blogspot.com/2008/08/human-waste-being-transformed-into.html">http://hydrogen-fuel-cell-car.blogspot.com/2008/08 ...</a>